(ATTN: UPDATES with more details in paras 3, 5-7, 8-9; ADDS with result of joint committee talks from para 10, new photos)

SEOUL, Sept. 16 (Yonhap) -- An inter-Korean factory zone in North Korea began its trial-run production on Monday after a five-month hiatus, as the two Koreas discuss ways to ensure sustainable growth of the joint economic venture.

Of the 123 South Korean firms with factories at the Kaesong Industrial Complex in the North's eponymous city, 90 started trial operations, with the aim of fully normalizing production thereafter, the Unification Ministry said. It said some 32,000 North Korean reported for work.